Flapper valve



July 14, 1959 R, E SYKES 2,894,528

FLAPPER VALVE Filed Dec. 3, 1954 v *5j M252@ United States, Patent` Company, Morton Grove, Ill., a corporation of Illinois Application December 3, 1954, Serial No. 472,988 3 Claims. (Cl. 137-238) Y My invention relates to apper valves and is con cernedvmore particularly with inlet and exhaust valves of this type which are employed in compressor operation such as the handling of air or gas.

One object of the invention is to provide a flapper valve structure which is characterized by a self-cleaning action as the at valving member thereof movesbetween closed .and open positions to thereby prevent accumulation or packing of dirt particles and other foreign matter beneath the member adjacent its secured portion which otherwise .would interfere with the full and free seating of the member.

-4 A further object is to providea structure of the character indicated in which the flat valve member is shaped as an annulus that is' secured in one limited zone thereof to .the valve body whereby the lift of the member is reduced for a given volume of air or gas ow and critical stresses are avoided in the member adjacent the fastening means.

These and further objects of the invention will be set forth in the following specification, reference being had to the accompanying drawing, and the novel means by which the objects are eifectuated will be definitely pointed out in the claims.

In the drawing:

Fig. l is a sectional elevation of a typical, single cylinder, air compressor which exemplies the application of the flapper valves.

Figs. 2 and 3 are enlarged sections of the inlet and exhaust valves, respectively, as they appear in Fig. l.

Figs. 4 and 5 are plan views of the inlet and exhaust valves looking in the directions of the arrows 4 and 5 in Figs. 2 and 3, all respectively.

Fig. 6 is a plan view of the valving member to reduced scale.

Referring to Fig. l of the drawing, the numeral 10 designates a single cylinder, air compressor which may be of conventional design and includes a main frame or crankcase 11, a cylinder 12 and a piston 13 reciprocable therein in the usual manner. A head 14 registers with the bore of the cylinder 12 and denes therewith a compression space 15. The head 14 is drilled and tapped in convenient locations to provide holes 16 and 17, respectively, Which communicate with the compression space 15.

Threaded in the lower portion of the hole 16 is an inlet valve and in the upper portion a lter assembly genl erally designated, respectively, by the numerals 18 and 19, while in the lower part of the hole 17 is threaded an exhaust valve and thereabove a relief valve generally designated by the numerals 20 and 21, respectively. The lter assembly may be conventional in design and such that air passing therethrough will be filtered to some extent before ilowing to the inlet valve 18 and the relief valve 21 may also be of the usual type and is specifically shown as being `of the spring loaded, ball type in which the ball opens at some determined compressor pressure as a safety factor.

The inlet valve 18 is more particularly illustrated in 2,894,528 Efatented July 14, 1959 Figs. 2, 4 and 6 to which reference will now be made. It includes a valve body 22 that is externally threaded for mounting in the hole 16 and an annular beveled surface 23 around the lower end thereof for sealing coaction with a similar surface in the head 14 to thereby eliminate any necessity for gaskets. The opposite or upper vend of the body 22 is coaxially recessed to spliningly receive a socket wrench plug 24 to facilitate mounting of the body in the hole 22. A plurality of passages 25 extend lengthwise through the body 22 and are circumferentially spaced therearound in a generally partiannular relation. The upper ends of the passages 25 communicate with the delivery side of the iilter assembly 19 while the lower ends terminate at the lower side of the body which is preferably a lapped surface 26. J

The lower or delivery ends of the passages 25 are normally closed by a fiat, annular and exing, valve member 27 of the liapper, springy type which is apertured in two adjacent locations 28 to receive a pair of rivets 29 by which the valve member is secured over .a limited zone thereof to the body 22. The spacing of the rivets 29 may be the same as that between adjacent pairs of passages 25.

From the foregoing, it will be apparent that the valve member 27' operates in the conventional manner, i.e., it fiexes downwardly to an open position during the Suction stroke of the piston 13 and closes during the compression stroke.

ln the usual type of apper valve which is fastened over a limited zone thereof to a valve body, dust and other foreign matter entrained in the air or gas being handled tend to collect between the body and member adjacent the fastening thereof and hence interferes with the full seating of the member. Ari important feature of the invention is a self-cleaning feature which prevents the dust accumulation by directing a portion of the air tiowing through the valve around the critical region.

The foregoing is accomplished by recessing a groove or channel 30 in the surface 26 close to and generally symmetrically related to the rivets 29. A convenient form of the groove 36 is the arc shape shown in Fig. 4, but whatever the shape, a portion of the groove registers with the central opening 31 through the valve member 27 and its ends open outwardly at the periphery of the body.

When the valve member 27 opens during the suction stroke of the piston 13, air moving through the passages 25 flows around the exed outer periphery and also through the central opening 31 of the valve member and a portion of the latter flow passes outwardly through the groove 30 for discharge at the periphery of the valve body 22. rhis action prevents packing or collection of dirt particles between the valve member and body adjacent the rivets 29 and so insures full seating of the valve member at all times during the compression stroke of Ithe piston.

A further feature is the use of the valve member 27 which may be annular as shown, but may have its outer periphery shaped as desired `so long as there is an opening through the member other than the rivet holes. This construction not only insures maximum air discharge for any given lift of 'the valve member, but also reduces stresses in the valve member compared to apper valves lacking a central air discharge opening.

The exhaust valve 20 through which air is discharged during the compression stroke of the piston to the exhaust passage 32 is generally similar to the inlet valve 18, but reversed as to the location of the valve member. The valve 20 therefore includes `a threaded valve body 33 having a plurality of passages 34 extending longitudinally therethrough which are related to each other in the same manner as the passages 25. The upper or delivery ends of the passages 34 terminate at the upper, lapped surface 35 of the body 33 and a valve member 36, generally similar to the -valve member 27, normally contacts the surface 35 in masking relation to the delivery ends ofthe passages 34. A pair of rivets 37 secure a limited portion of the valve member 36 to the body 33 in the same manner as the valve member 2'7 is secured and a groove 38, similar to the groove 30, is recessed in the surface 35 in the same relation to the valve member 36 and for the same purpose as stated in connection with the valve member 27 and groove 30. The use of a flapper valve member having a central opening therethrough also possesses the same advantages in this instance as recited for the inlet valve. The valve body 33 may also carry a socket Wrench plug 39 for threading the body 33 into the` opening 17 I claim:

l. A non-lubricated, self-seating, positive-sealing ilapper valve unit assembly comprising a cylindrical valve body having a at face at the delivery end thereof with a plurality of circumferentially spaced passages extending endwise through the body, said body having a threaded external attachment surface engageable in a correspondingly threaded cylinder head member and terminating adjacent the inner end of said body in a beveled annuar surface 25 haust valve unit assembly comprising a cylindrical valve body having a at outer end face withaplurality of Ycircumferentially spaced passages extending endwise through the body, said body having a threaded external attachment surface engageable in a correspondingly threaded cylinder head member and terminating adjacent the inner end of Said body in `a beveled annular surface for sealing, seating engagement with said member, said body having a Wrench-receiving socket opening centrally through the outer end face thereof, a at, exing valve member in the shape of an annulus for normally contacting the flat outer end face to mask the delivery ends of said passages, and means securing a limitedfportion of the member to the at face at a point spaced from the passage means, with the valve member having a central opening registering with said socket.

3. The Iarrangement of claim 2 wherein the at outer end face of said body has a groove recessed therein, said groove having a portion'registering with said valve member opening and extending tothe periphery of the body adjacent opposite sides of the securing means.

References Cited in the le of this patent UNITED STATES PATENTS 338,609 Nysewander Mar. 23, 1886 1,480,608 Gardner Jan. 15, 1924 1,679,012 Wilson July 31, 1928 1,783,599 Blake Dec. 2, 1930 2,107,998 Rullison Feb. 8, 1938 2,378,613 Young June 19, 1945 FOREIGN PATENTS 910,009 Germany Apr. 26, 1954 

